How to force AMDGPU to use full RGB range

Dec 1, 2018

I recently got an AMD GPU but sadly unlike i915 (Intel) and nvidia it doesn’t expose any way of setting the full RGB range which my monitor wants instead of limited. There are a dozen issues from the kernel, xorg, wayland compositors, etc to get this exposed somehow but
it still isn’t today.

Thankfully there is a hacky solution of using a custom EDID and this solution works on Wayland as well as Xorg (it should work with other drivers also). I was not actually the one to figure this out so shout out to parkerlreed on reddit. This post is just to make it more visible and I packaged the tool used to make this easier.

Find the edid file used by the connector: find /sys/devices/pci*/ -name edid